Aquinas - Summa Theologica v.3 - Theology Tools

120
P(2b)-Q(10)-A(2)-O(3) — Further, a gloss [*Augustine, Enchiridion lx.]
on 2 Corinthians 11:14 “Satan... transformeth himself into an angel of
light,” says that if “a wicked angel pretend to be a good angel, and be taken
for a good angel, it is not a dangerous or an unhealthy error, if he does or
says what is becoming to a good angel.” This seems to be because of the
rectitude of the will of the man who adheres to the angel, since his
intention is to adhere to a good angel. Therefore the sin of unbelief seems
to consist entirely in a perverse will: and, consequently, it does not reside
in the intellect.
P(2b)-Q(10)-A(2) — On the contrary, Things which are contrary to one
another are in the same subject. Now faith, to which unbelief is opposed,
resides in the intellect. Therefore unbelief also is in the intellect.
P(2b)-Q(10)-A(2) — I answer that, As stated above (P(2a), Q(74),
AA(1),2), sin is said to be in the power which is the principle of the sinful
act. Now a sinful act may have two principles: one is its first and universal
principle, which commands all acts of sin; and this is the will, because
every sin is voluntary. The other principle of the sinful act is the proper
and proximate principle which elicits the sinful act: thus the concupiscible
is the principle of gluttony and lust, wherefore these sins are said to be in
the concupiscible. Now dissent, which is the act proper to unbelief, is an
act of the intellect, moved, however, by the will, just as assent is.
Therefore unbelief, like faith, is in the intellect as its proximate subject.
But it is in the will as its first moving principle, in which way every sin is
said to be in the will.
Hence the Reply to the First Objection is clear.
P(2b)-Q(10)-A(2)-RO(2) — The will’s contempt causes the intellect’s
dissent, which completes the notion of unbelief. Hence the cause of
unbelief is in the will, while unbelief itself is in the intellect.
P(2b)-Q(10)-A(2)-RO(3) — He that believes a wicked angel to be a good
one, does not dissent from a matter of faith, because “his bodily senses are
deceived, while his mind does not depart from a true and right judgment”
as the gloss observes [*Augustine, Enchiridion lx]. But, according to the
same authority, to adhere to Satan when he begins to invite one to his
abode, i.e. wickedness and error, is not without sin.